This invention relates generally to an improved suction nozzle for use in unloading dry bulk particulate material from a container such as a vessel, barge or the like.
In the unloading of such dry bulk particulate material such as cement powder, grain or fertilizer, it is known that the material is fluidized when mixed with a transport medium, such as air, and thus may be conveyed and transported as if it were a fluid.
Systems utilizing suction techniques to transfer dry bulk particulate material are, of course, well known as described in U.S. Pat. No. 3,373,883, assigned to the Assignee of the present invention.
The prior art suction nozzles which were utilized in conjunction with such unloading systems suffered several disadvantages. A first disadvantage was the need for a blower or other source of external pressure to provide a transport medium such as air to fluidize and transport such material.
In an attempt to regulate the amount of transport air, elaborate pressure sensing damper mechanisms were developed. These of course were quite costly and not entirely satisfactory.
A second disadvantage with the prior art nozzles was caused by the nature of the particulate material. Specifically, with the prior suction nozzles, there was a significant amount of dust emission caused by the turning of the mechanical aerators and further that the nozzles did not perform satisfactorily when the level of particulate material remaining in the vessel was only of a shallow depth.